The invention relates in general to munitions and in particular to a munition fuze having multiple functions.
Projectile fuzes of today are required to meet stringent safety design requirements. These requirements include keeping sensitive primary explosives separate from the warhead until two different launch environments are sensed. These environments must each operate separate locks in the safety and arming (S&A) mechanism. Fuzes must also maintain the safety of the gun crew by delaying arming until the projectile is a safe distance from the gun.
There are a variety of different fuzes in production. Most fuzes are single purpose and include time fuzes, proximity fuzes, impact fuzes and impact delay fuzes. Several newer fuzes are so called multi-option fuzes, which accomplish a number of these tasks. These fuzes are generally electromechanical and integrate digital electronic circuitry with mechanical S&A's. The digital circuitry is used for time and proximity functions, while impact is generally done with simple analog circuitry. Delay after impact, if done at all, is a single, fixed delay. Fuzes used in relatively low launch acceleration environments such as mortars and artillery utilize quartz crystal oscillator clocked electronics. Quartz oscillators, however, are too delicate to reliably survive the high launch acceleration of tank gun and small caliber ammunition. For these higher launch acceleration environments, resistor capacitor (RC) clocked electronics are used.
The shortcoming of RC clocked circuitry is that RC frequencies vary greatly. They vary unit to unit, they vary with time, and they vary with temperature. To make an RC clocked circuit work accurately enough to be used in a time mode, the RC must be calibrated. This calibration is done at the time of setting, via a two-way data link with a quartz-clocked setter. While this is a valid technique, it can be too time consuming for certain situations.
For example, the current tank ammunition suite includes different rounds for different target types. Tanks travel with one round in chamber to rapidly attack an enemy vehicle. In such close combat encounters the first to shoot is usually the victor. Currently tanks must travel with a round chambered, which addresses the most likely or most threatening target, usually an armored target. However, if the target is not an armored target, then, for maximum effectiveness, the tank round must be changed to correspond to the new target.